1. Field of the Invention
The present invention relates to an imaging module including an image sensor and an optical member.
2. Description of the Related Art
Conventionally, various types of electronic imaging apparatus such as a digital camera, a video camera, an endoscope apparatus for observing an interior of an organ of a subject, and a mobile phone device having an imaging function have appeared. Among them, in the endoscope apparatus, an imaging module that mounts an image sensor is built in a distal end portion of a long and narrow insertion tool having flexibility. The endoscope apparatus is capable of observing a region to be observed or the like by inserting the insertion tool into a body cavity.
The imaging module has the image sensor built in, such as a CCD or a CMOS image sensor, images an optical image of an object on a light-receiving region of the image sensor by an optical system such as a lens, and captures image data of the object by photoelectric conversion processing by the image sensor.
Here, to relieve a burden on the subject or the like, it has been desired to downsize the diameter of the distal end of the insertion tool in the endoscope apparatus. In recent years, an imaging module has been proposed wherein a prism is placed on an image sensor arranged approximately parallel with an optical axis of an objective lens system in order to secure a sufficient light-receiving area on the image sensor even in a case where the area of a vertical surface with respect to the optical axis that can be used for the imaging module becomes small due to the downsizing of the diameter of the distal end of the insertion tool (for example, see Japanese Patent Application Laid-open No. 8-106055).